JP3756540B2 - transfer - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a transfer for a four-wheel drive (4WD) vehicle.
[0002]
[Prior art]
JP-A-2-212227 describes a transfer 201 as shown in FIG. The transfer 201 includes a planetary gear type center differential 203, a differential limiting device 205, a chain transmission mechanism 207, and the like. The engine driving force input from the internal gear 209 to the center differential 203 is output from the sun gear 211. It is transmitted to the rear wheel side via the shaft 213, and transmitted from the pinion carrier 215 to the front wheel side via the output shaft 217 and the chain transmission mechanism 207. The output shaft 217 is hollow and is disposed outside the output shaft 213. A differential limiting device 205 that limits the differential of the center differential 203 is disposed between the center differential 203 and the chain transmission mechanism 207.
[0003]
The differential limiting device 205 limits the differential by using a shear resistance of a viscous fluid sealed between the outer housing 219 and the inner hub 221, and there is no viscosity between the housing 219 and the hub 221. Oil seals 223 and 223 are arranged to prevent fluid leakage. The housing 219 is splined to the internal gear 209, and the hub 221 is splined to the outer periphery of the output shaft 217.
[0004]
[Problems to be solved by the invention]
As described above, there is a radial gap between the housing 219 and the hub 221 of the differential limiting device 205 in which the oil seals 223 and 223 are disposed, and the internal gear 209 and the output shaft 217 are connected to the spline, respectively. The housing 219 and the hub 221 are unbalanced due to the fact that both the housing 219 and the hub 221 can move somewhat, and the viscous fluid sealed between the housing 219 and the hub 221 is displaced. Since this vibration is input to the center differential 203 via the internal gear 209 and the output shaft 217 separately, it directly affects the tooth contact of each gear of the center differential 203, and the tooth contact of each gear. May cause defects, damage, noise, etc.
[0005]
Therefore, in the transfer 201, bushings 225 and 227 are disposed between the outer periphery of the output shaft 217 and the housing 219 to suppress the movement of the housing 219 and the hub 221.
[0006]
However, since the bushes 225 and 227 are arranged on the outer periphery of the output shaft 217 (double shaft) as described above, the oil in the oil passage 229 provided in the output shaft 213 is not connected to the output shaft 213 and the output shaft 217. Since the center differential 203 and the chain transmission mechanism 207 are disposed on both sides of the differential limiting device 205 in the axial direction, the oil is passed from the side of the bushing 225. , 227 is also difficult to supply. For this reason, in order to fully lubricate the bushes 225 and 227, forced oiling is required, and therefore a pump 230 is provided. For this reason, it is difficult to lubricate the bushes 225 and 227 without using the pump 230.
[0007]
Further, in order to improve the contact of each gear of the center differential, a bearing for separately supporting the transfer case 202 is provided between any of the center differential 203, the differential limiting device 205, and the chain transmission mechanism 207. Although it is conceivable that the output shaft 213 is supported at three points, any one of the bearings will be defective, and there is a possibility that the seizure may be locked or the defective bearing may be damaged.
[0008]
Accordingly, the present invention provides a transfer including a differential mechanism that distributes driving force to the front and rear wheels, and a differential limiting mechanism that limits differential rotation of the differential mechanism. In addition to blocking the differential mechanism and preventing problems due to tooth contact of the differential mechanism, the bearing lubrication is good without the need for a pump to lubricate the support portion of the differential limiting device. The purpose is to provide a transfer that does not require a separate bearing.
[0009]
[Means for Solving the Problems]
The transfer according to claim 1 is rotatably supported by a transfer case via a bearing, and a driving force from the engine is input thereto, and an input shaft having a first gear, and one end thereof is supported by the transfer case via the bearing. A first output shaft having the other end rotatably supported by the input shaft and having a second gear, and a second output having a third gear rotatably supported by a bearing on the outer periphery of the first output shaft. It is arranged at the end of the shaft and the input shaft and consists of the first gear, second gear and third gear, and distributes the driving force from the engine to the front wheel side and the rear wheel side via the first and second output shafts Differential mechanism, a power transmission mechanism disposed adjacent to the differential output in the axial direction and rotationally coupled to the second output shaft, and a housing side member disposed adjacent to the axial direction of the power transmission mechanism as the first or second output shaft. Rotating coupled to hub side Ri formed of wood from the rotation coupled differential limiting device in the second or first output shaft, the radial clearance and the hub-side member and the first output shaft of the hub-side member and the housing side member of a limited slip differential And the radial clearance between the housing side member and the second output shaft, or the radial clearance between the hub side member and the housing side member, and the diameter between the housing side member and the first output shaft. The sum of the gaps in the direction is set to be smaller than the gap in the radial direction between the hub side member and the second output shaft.
[0013]
[Action]
In the transfer according to the first aspect, one end of the first output shaft is rotatably supported on the transfer case via the bearing, and the other end is rotatably supported on the input shaft. The power transmission mechanism is adjacently disposed, the differential limiting device is adjacently disposed on the other axial side of the power transmission mechanism, and the housing side member or hub side member of the differential limiting device is rotationally coupled to the first output shaft.
[0014]
As described above, the first output shaft is supported at both ends by the bearings, and the housing side member or the hub side member of the differential limiting device is rotationally coupled to the first output shaft. Etc. are not given to the differential, and no special bearing is required to support the transfer case.
[0015]
Further, unlike the conventional example of FIG. 3, the differential limiting device 205 sandwiched between the differential mechanism (center differential 203) and the power transmission mechanism (chain transmission mechanism 207) is an outer periphery of the output shaft 217 which is a double shaft. Since the bearings (bushings 225, 227) which are difficult to lubricate are not required, the bearings are not lubricated poorly. Also, since the bearing that supports the second output shaft is disposed between the second output shaft and the first output shaft (inside the second output shaft), the oil is good and can be sufficiently lubricated with natural oil supply. .
[0016]
Further, the transfer according to the first aspect of the present invention is (the radial gap between the housing side member and the hub side member plus, the radial gap between the hub side member and the first output shaft) <(the housing side member and the second gap). (Radial gap between the output shaft) or (radial gap between the housing side member and the hub side member plus, radial gap between the housing side member and the first output shaft) <(hub side member and first 2) (gap in the radial direction with respect to the output shaft).
[0020]
【Example】
An embodiment of the present invention will be described with reference to FIGS . FIG. 1 shows an embodiment, and FIG. 2 shows a power system of a vehicle in which this embodiment is used. The upper part of FIG. 1 corresponds to the front of this vehicle. Further, members and the like that are not given reference numerals are not shown.
[0021]
As shown in FIG. 2, the power system includes an engine 1, a transmission 3, a transfer 5 according to the embodiment, a propeller shaft 7 on the front wheel side, a front differential 9 (a front wheel side differential device), front axles 11 and 13, and left and right front wheels. 15 and 17, a rear wheel side propeller shaft 19, a rear differential 21 (rear wheel side differential device), rear axles 23 and 25, left and right rear wheels 27 and 29, and the like.
[0022]
The driving force of the engine 1 is transmitted from the transmission 3 to the vertical transfer 5, transmitted from the transfer 5 to the front differential 9 and the rear differential 21 via the propeller shafts 7 and 19, and further from the front differential 9 to the left and right It is distributed to the front wheels 15 and 17 and distributed from the rear differential 21 to the left and right rear wheels 27 and 29.
[0023]
As shown in FIG. 1, the transfer 5 includes a center differential 31 (differential mechanism), a chain transmission mechanism 33 (power transmission mechanism), a speed-sensitive differential limiting device 35, and the like. They are laid out in the correct order.
[0024]
The center differential 31 is a double pinion planetary gear mechanism. The internal gear 37 (first gear) is integrally formed at the rear end of the input shaft 39. The input shaft 39 passes through the front end of the transfer case 41 and is splined to the output shaft 43 (FIG. 2) of the transmission 3. ing. The input shaft 39 is supported on the transfer case 41 by a single-seal ball bearing 45 and a ball bearing 47. An oil reservoir is formed at the bottom of the transfer case 41, and a seal 49 is disposed between the input shaft 39 and the transfer case 41 to prevent oil leakage.
[0025]
The outer and inner pinion gears 51 and 53 (second gears) are supported by pinion shafts 57 via bushes 55, and each pinion shaft 57 is supported at both ends by front and rear pinion carriers 59 and 61. The pinion carriers 59 and 61 are connected to each other, and the front-side pinion carrier 59 is splined to the output shaft 63 (first output shaft) on the rear wheel side. Thrust washers 65 and 66 for reducing the sliding resistance are disposed between the pinion carrier 59 and the input shaft 39.
[0026]
Further, the front end of the output shaft 63 is supported by a recess 69 of the input shaft 39 via a bearing 67 disposed on the inner diameter portion of the bearings 45 and 47 of the input shaft 39, and the rear end of the output shaft 63 is transferred via a ball bearing 71. It is supported by. The output shaft 63 is spline-connected to a connecting shaft 73 (FIG. 2) on the propeller shaft 19 side, and a seal 75 is disposed between the connecting shaft 73 and the transfer case 41 to prevent oil leakage.
[0027]
The sun gear 77 (third gear) is integrally formed with a hollow front wheel side output shaft 79 (second output shaft), and this output shaft 79 is supported on the outer periphery of the output shaft 63 via bearings 81 and 81. .
[0028]
The chain transmission mechanism 33 includes a pair of sprockets 83 and 85 and a chain 87 for connecting them. The sprocket 83 is spline-connected to the outer periphery of the output shaft 79, and the sprocket 85 is connected to the transmission shaft 89 (intermediate shaft) on the front wheel side. It is integrally formed. The transmission shaft 89 is disposed in parallel with the output shaft 79 and is supported on the transfer case 41 by ball bearings 91 and 93. The transmission shaft 89 is splined to a connecting shaft 95 (FIG. 2) on the propeller shaft 7 side, and a seal 97 is disposed between the connecting shaft 95 and the transfer case 41 to prevent oil leakage. Yes.
[0029]
The driving force of the engine 1 input from the input shaft 39 to the center differential 31 is distributed from the pinion gears 51 and 53 and the pinion carriers 59 and 61 to the output shaft 63, and from the sun gear 77 to the output shaft 79, and from the output shaft 63 to the rear wheel. 27, 29 and transmitted from the output shaft 79 to the front wheels 15, 17 via the chain transmission mechanism 33. Further, when a driving resistance difference occurs between the front and rear wheels on a rough road or the like, the driving force of the engine 1 is differentially distributed to the front and rear sides by the rotation of the pinion gears 51 and 53.
[0030]
The differential limiting device 35 is a speed-sensitive device that limits a rotational difference (differential) generated between the outer housing 99 (housing side member) and the inner hub 101 (hub side member). And the hub 101 are filled with viscous fluid, and since the housing 99 and the hub 101 have a gap C for enabling relative rotation, oil seals 103 and 103 for preventing leakage of the viscous fluid are provided. Has been placed. The housing 99 is splined to the output shaft 79 with a radial gap A, and the hub 101 is splined to the output shaft 63 with a radial gap B. The differential rotation of the center differential 31 is The limiting force is limited by the differential limiting device 35, and the higher the differential speed between them, the stronger the differential limiting force.
[0031]
Note that the total of the radial gap C between the housing 99 and the hub 101 and the radial gap B between the hub 101 and the output shaft 63 is greater than the radial gap A between the housing 99 and the output shaft 79. It is formed small. One end of the housing 99 abuts against the sprocket 83 at the abutment 130 so that movement of the differential limiting device in one axial direction (leftward) is restricted, and the hub 101 and the output shaft 63 are in contact with each other. By abutting at the contact portion 140, the movement of the differential limiting device in the other axial direction (right direction) is restricted.
[0032]
As described above, the front end of the output shaft 63 to which the hub 101 is connected is supported by the transfer case 41 via the bearing 67, the input shaft 39, and the ball bearings 45 and 47, and the rear end of the output shaft 63 is the ball bearing 71. Further, the output shaft 79 to which the housing 99 is coupled is supported on the outer periphery of the output shaft 63 via bearings 81 and 81, so that the rotation of the housing 99 and the hub 101 is performed. The adverse effects due to vibrations are blocked from the center differential 31 by these bearings 45, 47, 71, 81, 81, preventing tooth contact defects, breakage, noise, and the like.
[0033]
As shown in FIG. 1, an oil garter 105 is attached to the transfer case 41, and an oil sump 107 is formed at the front portion of the transfer case 41 by an input shaft 39, a seal 49, and a single seal ball bearing 45. Yes. The input shaft 39 is provided with oil inflow oil passages 109 and 111, and the output shaft 63 is provided with an axial oil passage 113 and a radial discharge oil passage 115. Further, a blind plate 117 that prevents oil from flowing out is attached to the transfer case 41, and an oil separator 119 is attached to the transfer case 41 and the axial oil passage 113 of the output shaft 63.
[0034]
When the sprockets 83 and 85 and the chain 87 rotate, the oil gathered in the oil gutter 105 from the oil reservoir of the transfer case 41 as shown by the arrow 121 is collected as shown by the arrow 123 by the inclination of the oil gutter 105. The oil flows into the oil reservoir 107 and further flows into the inflow oil passages 109 and 111 of the input shaft 39.
[0035]
The oil passing through the inflow oil passage 111 is guided to the bearing 67 to lubricate it, and further the thrust washer 65 is lubricated. Further, the oil passing through the inflow oil passage 109 moves in the axial direction through the axial oil passage 113, receives the centrifugal force due to the rotation of the output shaft 63, and the bearings 81, 81 of the output shaft 79 from the radial discharge oil passage 115. The oil is supplied to the oil and lubricated, and a part of the oil flows to the left in the axial direction and lubricates the thrust washer 66, and then is supplied from the front end of the output shaft 79 to the pinion gears 51 and 53 side. Moves in the gap B between the housing 101 and the output shaft 79.
[0036]
Unlike the conventional bushes 225 and 227 arranged outside the output shaft 217, the bearings 81 and 81 are only arranged inside the output shaft 79, so that oil can easily reach them, and the differential limiting device 35. Since no rotation member is provided on one side, sufficient lubrication is possible independently, so the length up to the inner diameter portion of the axial oil passage 113 and the sprocket 83 is sufficient, and centrifugal force is used. Thus, sufficient lubrication is possible with natural lubrication as described above.
[0037]
The oil splashed by the rotation of the center differential 31, the chain transmission mechanism 33, the differential limiting device 35, etc. bounces off the inner wall of the transfer case 41, and each gear of the center differential 31 and the ball bearings 45, 47, 71, Lubricate 91, 93, etc.
[0038]
Thus, the transfer 5 is configured.
[0039]
As described above, the transfer 5 has the chain transmission mechanism 33 disposed between the center differential 31 and the differential limiting device 35, and the output shafts 63 and 79 that connect the center differential 31 and the differential limiting device 35. By supporting each with a bearing, the rotational vibration of the differential limiting device 35 is blocked from the center differential 31 to prevent tooth contact failure, breakage, noise, and the like of each gear.
[0040]
Further, lubrication such as bushes 225 and 227 sandwiched between the center differential 203 and the chain transmission mechanism 207 as in the conventional example of FIG. 3 and disposed outside the output shaft 217 (double shaft). Since difficult bearings are unnecessary, there is no bearing lubrication failure. Further, since the bearings 81 and 81 are arranged inside the output shaft 79 so that the oil can easily reach, sufficient lubrication is possible by natural lubrication using the centrifugal force as described above.
[0041]
In the present invention, the differential mechanism may be a planetary gear type or bevel gear type differential mechanism in which the driving force of the engine is input to the pinion carrier and output from the internal gear and sun gear.
[0042]
Further, the differential limiting device is not limited to the one using the shear resistance of the viscous fluid as in the embodiment, and may be a differential limiting device for fastening a multi-plate clutch with a hydraulic actuator or an electromagnet, for example.
[0043]
Further, the power transmission mechanism is not limited to the chain transmission mechanism, and may be a gear transmission mechanism, for example.
[0044]
【The invention's effect】
In the transfer according to the first aspect, one end of the first output shaft is rotatably supported on the transfer case via the bearing, and the other end is rotatably supported on the input shaft. The power transmission mechanism is adjacently disposed, the differential limiting device is adjacently disposed on the other axial side of the power transmission mechanism, and the housing side member or the hub side member of the differential limiting device is rotationally coupled to the first output shaft. Without requiring special bearings to support the transfer case, it prevents tooth contact failure, breakage, and noise.
[0045]
Further, unlike the conventional example, there is no bearing which is sandwiched between the differential mechanism and the power transmission mechanism and arranged on the outer side of the double shaft, which is difficult to lubricate.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of the present invention.
FIG. 2 is a skeleton mechanism diagram showing a power system of a vehicle using this embodiment.
FIG. 3 is a cross-sectional view of a conventional example.
[Explanation of symbols]
5 Transfer 31 Center differential (differential mechanism)
33 Chain transmission mechanism (Power transmission mechanism)
35 Differential limiter 37 Internal gear (first gear)
39 Input shaft 41 Transfer case 45, 47 Ball bearing (bearing)
51, 53 Pinion gear (second gear)
63 Rear wheel side output shaft (first output shaft)
77 Sun gear (3rd gear)
79 Front wheel output shaft (second output shaft)
81 Bearing 83, 85 Sprocket 87 Chain 89 Transmission shaft (intermediate shaft)
105 Oil garter 107 Oil reservoir 109 Inflow oil passage 113 Axial oil passage 115 Discharge oil passage

Claims (1)

The transfer case is rotatably supported through a bearing and the driving force from the engine is input, and the input shaft having the first gear and one end supported by the transfer case through the bearing and the other end rotated to the input shaft A first output shaft that is freely supported and has a second gear, a second output shaft that is rotatably supported through a bearing on the outer periphery of the first output shaft, and an end of the input shaft A differential mechanism that is arranged in a portion and that includes a first gear, a second gear, and a third gear, and distributes the driving force from the engine to the front wheel side and the rear wheel side via the first and second output shafts; A power transmission mechanism disposed adjacent to the axial direction of the dynamic mechanism and rotationally coupled to the second output shaft; and a hub side member disposed adjacent to the axial direction of the power transmission mechanism and rotationally coupled to the first or second output shaft of the housing side member. The second or first output shaft Ri consists the rotation coupled differential limiting device, the sum of the radial gap between the radial gap and the hub-side member and the first output shaft of the hub-side member and the housing side member of a limited slip differential The sum of the radial gap between the housing side member and the second output shaft or the radial gap between the hub side member and the housing side member and the radial gap between the housing side member and the first output shaft is the hub side member. The transfer is characterized in that it is set smaller than the radial gap with the second output shaft .

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